By Grant McCarty
Local Foods and Small Farms Educator, University of Illinois Extension
As July is coming to an end and you are harvesting the first tomatoes and peppers, now is the time to begin planning and planting for cool season vegetables.
Cool season vegetables are those that are cold hardy with the ability to withstand cold air and soil temperatures. They can tolerate our first frost and in some cases, our first hard freeze. These vegetables are those that you plant in the spring before your warm season crops. In fact, you may still be enjoying some of these vegetables such as kale. Some cool season vegetables are known to “bolt.” For a plant to “bolt”, it means that it has gone to seed. This happens often with lettuce and spinach as hot weather will make these both “bolt” and send up seeds.
Cool season vegetables include kale, radish, spinach, cabbage, broccoli, lettuce (both head and leaf), kohlrabi, and other plants. While garlic is a cool season vegetable, you should not plant it until around the first week of September.
For fall harvest of cool season vegetables, you need hot weather. Many of these plants are direct seeded into the garden. These seeds need the warmer soil and weather to properly germinate. This includes spinach, lettuce, radish, carrots, and others. If you wait too late to sow these seeds, they will not germinate properly or germinate at all. Direct-seeded cool season vegetables can be sowed from now until mid-August.
Cool season vegetables purchased as transplants are not as dependent on the warmer soil and weather. Still, you should aim to have these planted in the next couple of weeks. Some cool season vegetables purchased as plants include kale, head lettuce, cabbage, kohlrabi, and broccoli. If you still have warm season vegetables in place, you can plan your rows near these plants. As the summer crop declines, your fall crops will be able to come in.
The trick to a cool season vegetable garden is knowing if it is direct-seeded or a transplant. From there, you’ll be able to get your garden started off right and be harvesting from your backyard in October and November.